textproduct: Albany

WHAT HAS CHANGED

A cold front tracking through the region tonight has sped up resulting in rainfall arriving earlier today. Rain is now expected to overspread much of eastern NY starting late this afternoon before reaching western New England by early evening. Rain also ends sooner with most the moderate/steady rain ending by 06 UTC Friday and lingering showers ending by 12 UTC Friday. Rainfall amounts have also increased slightly for areas from I-90 southward with amounts now ranging from 0.50 - 0.75".

KEY MESSAGES

1) A period of moderate rainfall is likely from the I-90 corridor southward late this afternoon into this evening but will likely not result in flooding impacts. Then, there is low to medium confidence for multiple periods of precipitation during the middle to end of next week that may result in isolated flooding.

DISCUSSION

KEY MESSAGE 1...

A warm front lifting through the Northeast this morning will settled around the North Country by this afternoon. Strong southwest winds in its wake will usher in the warm sector. With forecast soundings showing the boundary layer becoming well mixed, there is high confidence for temperatures to exceed 60 degrees outside of the southern Greens and southwest Adirondacks this afternoon. Enjoy the warm weather while it lasts as the boundary to our north drops southward late this afternoon into this evening as broad troughing over southern Canada shifts eastward. Rather impressive west-southwest winds in the low and mid-levels will direct a moisture plume out of the Ohio Valley eastward as height falls and weak shortwaves riding along the boundary result in periods of rain starting late this afternoon (21 - 00 UTC) initially in eastern NY before spreading into western New England early this evening.

By the time the stronger forcing and moisture transport arrive late afternoon, the boundary looks to settle across the I-90 corridor. Thus, periods of steady/moderate rainfall should actually miss the southern Adirondacks and Upper Hudson Valley and become focused in the Mohawk Valley, Capital District, western MA before sliding southward early this evening. The impressive moisture transport plus weak elevated instability will likely support periods of moderate rainfall with the 3-hrly probabilistic match mean (PMM) precip values from the HREF ranging 0.10 - 0.50" between 21 UTC and 03 UTC Friday. After 03 UTC, steady/moderate rain exits to our south and east with just some lingering light showers through 09 - 12 UTC Friday as the front continues to shift southward. Winds shift abruptly to the north/northeast behind the front with low-level cold air advection allowing tempertures to fall into the 20s and 30s by early Friday. Temperatures turn 5 to 15 degrees below normal Friday and Saturday. Saturday will be the chilliest day where there is a greater than 75% chance for high temperatures to fall below 40 degrees nearly regionwide.

Next focus will be on the middle to end of next week where there is increasing confidence that ridging in the southern tier of the country shifts further eastward while multiple shortwaves continue to track across southern Canada. This pattern looks to favor increased moisture transport from the Gulf and a warming temperature trend while the shortwaves provide opportunities for multiple sfc boundaries that can help focus the moisture resulting in periods of precipitation. While there remains considerable uncertainty in the exact timing and placement of boundaries and ensuing areas of precipitation, the latest NBM probabilistic guidance shows 30 to 50% chance for greater than 1" of precipitation across eastern NY and western New England between 7AM Wed and 7AM Fri. Latest MMEFS using the GEFS and NAEFS for QPF/snow melt (mainly from the southwest Adirondacks) as input show 10 to 30% chance for action and minor flood stage along our faster responding rivers through the end of next week. Even though confidence for any flooding impacts remains low, we will continue to closely monitor forecast trends through the coming days.

AVIATION /18Z THURSDAY THROUGH TUESDAY/

Through 18z Friday...VFR conditions prevail across all TAF sites this afternoon as visible satellite imagery shows high clouds streaming into the region ahead of an incoming frontal system. Ceilings will continue to develop and lower through the afternoon, though VFR conditions should remain in place. By this evening, rain begins to move in from northwest to southeast, gradually spreading into terminal boundaries by this evening. Initially, rainfall rates should be rather light, especially considering there is a fair amount of dry air to be overcome in the lower levels. Visibilities should therefore remain unaffected with ceilings lowering into low-end VFR thresholds.

As the column moistens and forcing for ascent increases just ahead of the front, rainfall will become more steady with rates potentially becoming more moderate. There are some differences in the guidance pertaining to the timing of these more moderate to locally heavy rates as well as their locations. That said, generally it looks as though each terminal could have some steadier rain between 02-08z so TEMPO groups were included accordingly. MVFR conditions can largely be expected within these periods of moderate rainfall, though some patchy IFR conditions cannot be ruled out due to lowered ceiling heights.

Behind the front, rain clears out fairly quickly tomorrow morning, but some lingering showers could occur particularly at KALB as some of the guidance hints at the potential for some localized convergence through daybreak. But upon the conclusion of these, conditions will begin to improve as at all other terminals with VFR conditions anticipated to return by the end of the 18z cycle.

Winds will begin the period prevailing out of the southwest at sustained speeds ranging from about 8-12 kt. By tomorrow, though, winds will shift to the northwest behind the front and become breezy with sustained speeds ranging from 10-15 kt and gusts up to 25 kt.

Outlook...

Friday Night: No Operational Impact. NO SIG WX. Saturday: No Operational Impact. NO SIG WX. Saturday Night: No Operational Impact. NO SIG WX. Sunday: No Operational Impact. NO SIG WX. Sunday Night: No Operational Impact. NO SIG WX. Monday: Low Operational Impact. Breezy. Slight Chance of RA. Monday Night: Low Operational Impact. Slight Chance of RA. Tuesday: Moderate Operational Impact. Chance of RA.

ALY WATCHES/WARNINGS/ADVISORIES

CT...None. NY...None. MA...None. VT...None.